Electrical pattern mechanism for circular knitting machines

ABSTRACT

An electrical pattern mechanism for a circular knitting machine having a rotary needle cylinder and electromagnetically actuated adjusting components which act either directly on needles or on jacks and which are controlled by information derived from a program carrier. A bistable electronic sweep circuit has one or the other of its conditions determined by the information in the control signal derived from the program carrier. This sweep circuit has a pair of outputs connected through one of a pair of univibrators with one of a pair of electromagnetic windings. One of the univibrators is connected with one of these windings together with a time-limited current amplifier circuit.

United States Patent Groezinger ELECTRICAL PATTERN MECHANISM 51 May 30, 1972 FOREIGN PATENTS OR APPLICATIONS FOR CIRCULAR I I ITTING] IACHH 1,474,081 2/ 1967 France ..66/50 R [72] Inventor: Gerhard Groezinger, Wurttemberg, Ger- 1,486,978 1967 France 0 R many 1,917,574 11/1969 Germany ..66/50 [73] Assigneez 21235;: Cie, Tailfingen (Wuerttemberg), Primary Examiner wm carter Reynolds y Attorney-Arthur o. Klein [22] Filed: Jan. 21, 1970 [21] Appl. No.: 4,675 [571 ABSTRACT An electrical pattern mechanism for a circular knitting [30] Foreign Application Priority Data machine having a rotary needle cylinder and electromagnetically actuated ad usting components which act either directly Jan. 24, Germany on needles o on jacks and are ontrolled information derived from a program carrier. A bistable electronic [52] U.S. Cl. ..66/50 R Sweep circuit has one or the other ofits conditions determined [51] I11!- Cl. ..D04b 15/78 by the information in the control Signal derived from the Fleld Of Search 50, A, B, A g carrier. Sweep circuit has a p of outputs con nected through one of a pair of univibrators with one of a pair [56] References Cited of electromagnetic windings. One of the univibrators is con- UNITED STATES PATENTS nected with one of these windings together with a time-limited current amplifier circuit. 3,446,037 5/1969 Sutton ..66/25 3,470,714 10/1969 Corbaz ..66/50 R 2 Claims, 1 Drawing Figure Patented May 30; 1972 INVENTOR.

BY: Gerhard Gr'z/nyer Mam fittarnev ELECTRICAL PATTERN MECHANISM FOR CIRCULAR KNITTING MACHINES BACKGROUND OF THE INVENTION The present invention relates to circular knitting machines.

ln particular, the present invention relates to electrical pattern mechanisms for such machines where the latter has a rotary needle cylinder and electromagnetically actuated adjusting or setting components controlled according to a predetermined pattern and acting either directly on needles or on jacks which transmit movement to the needles, a suitable program carrier being provided to deliver the control impulses to the electromagnets which actuate the adjusting components.

Electrical pattern mechanisms for knitting machines are controlled according to a predetermined program which is stored on a suitable program carrier such as, for example, a film strip or a punch tape, in a suitably coded form. In accordance with the desired pattern the knitting operations will be carried out in accordance with a particular program. The selection of the needles which are to operate at the knitting locations of the machine takes place by way of electromagnets and through control or adjusting components actuated by these electromagnets. The excitation of the electromagnets is regulated by the program carrier.

With arrangements of this general type the signals are not always transmitted in the most reliable manner. There is a considerable waste of power and the structure is relatively complex and expensive. Thus, for example, if it is required that certain signals be repeated one after the other, the very same structure is required to continuously operate over and over through the same cycle in order to bring about the required operations, and this gives rise to a considerable waste of power as well as to the requirement of a bulky-complex structure which is a source of frequent faulty operations.

SUMMARY OF THE INVENTION A primary object of the present invention is to provide an electrical structure of the above general type which is capable of actuating electromagnets, which control the knitting components, in a fully reliable manner and in accordance with the different information contained in control impulses supplied by a program carrier.

In particular, it is an object of the invention to provide a construction of this type which will bringabout a change in the operations when a signal changes from a non-knitting to a knitting signal, and which is capable of saving a considerable amount of power as well as increasing the efi'lciency and accuracy of the operation by maintaining the parts in predetermined positions if successive signals are the same.

According to the invention, a bistable electronic sweep circuit is provided, and the position of this circuit is determined by the information content of a control signal supplied from a program carrier. This sweep circuit has a pair of outputs one of which is connected through a univibrator and a time-limited current amplifier with an electromagnetic winding. The univibrators can take the form of so-called mono-flop circuits. The bistable sweep circuit can be formed in a particularly suitable manner by a so-called flip-flop circuit having a pair of inputs receiving control signals through AND circuits. These inputs of the flip-flop circuit transmit the different control signals from the program carrier and from synchronizing impulses.

The time-limited current amplifiers can each be formed by a capacitor and an ohmic resistor which are connected in parallel with each other. The parallel connected capacitor and resistor are in turn placed in series with one of the electromagnetic windings in the emitter/collector path of a transistor, with the parallel connection and the magnetic winding being bridged by a one-way rectifier.

The electrical pattern mechanism formed by the structure for transmitting the electronic control signals according to the invention is capable of being used for different electromagnetic actuating devices forming parts of such pattern mechanisms. The components for needle selection or the jacks which control the needles can, for example, take the form of a special electromagnet usedfor pushing in or pulling out a switching component, with the controls derived according to the invention being produced in accordance with the information content of a momentarily effective control signal, particularly an impulse-type control signal, to bring about excitation of one or the other of a pair of. control magnets which respectively produce the different operations. The control signal transmission, according to the invention, can also be used with a single electromagnet, which has either a pair of special exciting coils of oppositely wound directions or a single exciting coil with a current reversing connection. The latter construction is provided, for example, by a so-called direct current reversing magnet. Each switching magnet or pair of switching magnets of the knitting machine is provided with a control signal transmitting circuit of the invention.

BRIEF DESCRIPTION OF THE DRAWING The invention is illustrated by way of example in the accompanying drawing which form part of this application and in which there is illustrated the wiring diagram of one possible embodiment of a control signal transmitting circuit for an electrical pattern mechanism, in accordance with the invention.

DESCRIPTION OF PREFERRED EMBODIMENT In the circuit which is illustrated in the drawing, there are five connecting junctions 1 5. Of these connecting junctions, the junction 1 is electrically connected with a positive pole of a first source of direct current. The junction 2 is electrically connected with the positive pole of a second source of direct current having a potential which is at least half as small as the potential of the direct current of the first source. The connecting junction 5 is connected with the common negative pole of bothof these direct current sources. The unillustrated program carrier transmits two types of control signals to the connecting junction 3. These two types of control signals are respectively one type of signal providing a knitting signal and a second type of signal providing a non-knitting signal. Both types of control signals can take the form of impulses of different amplitudes or duration, or these signals may simply be characterized by the presence or absence of a control potential. The signals are evaluated in a suitably formed integrating logic circuit 6, so that the knitting impulse activates the input 71 of an AND gate 7 while the non-knitting" control signal activates the input 81 of a second AND gate 8. The other inputs 72 and 82 of both of the AND gates 7 and 8 are activated through synchronizing impulses which are supplied in accordance with the speed of rotation of the circular machine and are transmitted through the connecting junction 4 into the circuit .6.

This integrated logic input circuit 6 is electrically connected with a known sweep circuit in the form of a flip-flop circuit or bistable multivibrator 1 1 made up of a pair of transistors 9 and 10. This flip-flop circuit 11 has one input 111 leading to the base of the transistor 9 and connected through a diode 12 with the output 83 of the AND gate 8. The second input 112 of the flip fl0p circuit 11 is connected through a diode 13 with the output 73 of the AND gate 7. This input 112 leads in a known way to the base of the other transistor 10 of the sweep circuit 1 l.

The pair of outputs 113 and 114 of the flip-flop circuit 11 are respectively connected through coupling capacitors 14 and 15 with the input of mono-flop circuits 16 and 17, respectively forming a pair of univibrators. Both of these mono-flop circuits 16 and 17 are of the same construction; circuit 16 consists primarily of a pair of transistors 161, 162 and a countercoupling capacitor 163. Circuit 17 includes transistors 171, 172 and a counter-coupling capacitor 173. The outputs 164 1 and 174 are respectively connected with the base of power transistors 18- and 19. The emitter/collector paths of the power transistors 18 and 19, which act as switching means, are respectively in series with a parallel connection between ohmic resistors 20 and 21 and a capacitor 22 and 23 and in series with an electromagnetic winding 24 and 25 between the connecting junctions and 1 of the circuit. In addition the collectors of both power transistors 18 and 19 are respectively connected through one-way rectifier 26 and 27 with the connecting junction 1.

The above-described circuitry operates as follows:

If the connecting junction 3 receives a non-knitting control signal, the input 81 of the AND gate 8 is activated. With a synchronizing signal received at the connecting junction 4 and thus transmitted to the second input 82 of the AND gate 8, this AND gate 8 supplies at its output 83 during the simultaneous activation of both inputs 81 and 82 an output signal which reaches the base of the transistor 9 of the flip-flop circuit 11 and blocks this transistor 9. As a result the circuit 11 changes over to its other stable condition in which the transistor is conductive and thus the output potential present at the output 1 13 of the flip-flop circuit 1 l deteriorates and disappears. The decreasing leg of the output signal brings about a switching of the mono-flop circuit 16 which is laid out in such a way that it changes its stable condition for a predetermined relatively short time and during this time opens the power transistor 18. With the opening of the power transistor 18 thecapacitor 22 becomes charged, this capacitor 22 being in parallel with the ohmic resistor 20 and thus practically bridging the resistor 20 during the charging operation. The resistor 20 is therefore, during the period of charging of capacitor 22, not effective as series resistance for the electromagnetic winding 24, so that this winding 24 which is normally designed for the potential at the junction 2 will instead receive the higher potential at the junction 1 which is connected with the first of the above-mentioned sources of direct current, so that the winding 24 is excited with an overpotential. In this way, an exceedingly reliable response of the electromagnet and a reliable actuation of its armature and a motion transmitting element connected thereto and acting on the jack of the knitting machine which is to be controlled is assured. After charging of the capacitor 22 the series resistor 20 becomes fully effective and thus, the overpotential at the electromagnet 24 deteriorates so that there can be no harmful overloading at this latter winding period.

With the above-assumed condition of the circuit, nothing will change as long as the junction 3 receives nonknitting signals. Only when a knitting" signal is received at the junction 3 and thus, there is an activating of the one input 71 of the AND gate 7 will there be upon occurrence of a synchronim'ng signal 72 at the second input of the AND gate 7 an output signal 73 which reaches the second input 112 of the flip-flop circuit 11 to block the transistor 10 and thus again return the flip-flop circuit into its first stable condition. In this latter stable condition an output signal builds at the first output 113 while the output signal previously present at the second output 114 disappears, with the decreasing leg of this latter diminuishing signal connecting the mono-flop circuit 17 to render the latter active. In this way during a predetermined interval of time the power transistor 19 is opened, resulting in charging of the capacitor 23 and thus excitation of the electromagnetic winding 25 with an overpotential, as was described above in the first case in connection with electromagnetic winding 24. The pair of electromagnetic windings 24 and 25 can, for example, take the form of special exciting windings of a common control magnet, but have different directions of winding so that with the one winding the armature of the magnet is brought into a first control position while with the other winding the armature of the magnet is brought into its opposed second control position. The pair of electromagnetic windings 24 and 25 can, however, also take the form of special electromagnets which operate upon a common control element to move the latter in different directions. Both the windings 24 and 24 can, however, also symbolize different excitation conditions of a single exiting coil of a direct current reversin ma et.

With e a ve-descnbed control signal transmitting circuit of the invention, used in an electrical pattern mechanism of a knitting machine, there is a reliable separation between the control signals in accordance with the information content thereof, and the electrical control magnets are very reliable actuated. Moreover, once the circuit of the invention excitation of the magnets will take place only when there is a change in the control signal. Thus, when the signal changes from non-knitting" to knitting" or the reverse, the result will be excitation of the control magnets in the manner described above. A series of the same type of control signals, in other words, a series of knitting" signals following each other or a series of non-knitting" signals following one another, will thus not produce a series of the same type of excitation of the electromagnets, because such a series of the same signals will not actuate the flip-flop circuit. In this way, there is a very significant saving of energy and a corresponding reduction in the heating of the electromagnets. The power loss of an electrical pattern mechanism thus can be very considerably reduced with the present invention.

Although my invention has been illustrated and described with reference to the preferred embodiment thereof, 1 wish to have it understood that it is in no way limited to the details of such an embodiment but is capable of numerous modifications within the scope of the appended claims.

What is claimed is:

1. In a circular knitting machine, apparatus for selectively positioning a needle-actuating 'magnetic armature between first and second positions in response to transitions between first and second control signals individually indicative of knitting and non-knitting commands, which comprises:

first and second separately excitable control windings electromagnetically associated with the armature for moving the armature from the first to the second position when the first winding is excited and for moving the armature from the second to the first position when the second winding is excited; a bistable multivibrator having first and second complementary inputs and first and second complementary outputs;

means responsive to each occurrence of the first control signal for exciting the first input of the bistable multivibrator;

means responsive to each occurrence of the second control signal for exciting the second input of the bistable multivibrator;

means including first and second normally disabled switching means for individually exciting the first and second windings when the switching means are enabled; means responsive to the first output of the bistable multivibrator for enabling the first switching means; and means responsive to the second output of the bistable multivibrator for enabling the second switching means.

2. In an electrical pattern mechanism for circular knitting machines having a rotary needle cylinder and electromagnetically actuated components acting on the needles or jacks according to control signals derived from a program carrier:

a bistable multivibrator whose output states are determined by the control signals supplied by the program carrier;

a monostable multivibrator having an input connected to an output of the bistable multivibrator;

a resistor;

a capacitor connected across the resistor;

an electromagnetic winding;

a transistor;

winding excitation means including means for serially connecting the resistor, the winding, and the collectoremitter path of the transistor; and

means for coupling the output of the monostable multivibrator to the base of the transistor. 

1. In a circular knitting machine, apparatus for selectively positioning a needle-actuating magnetic armature between first and second positions in response to transitions between first and second control signals individually indicative of knitting and non-knitting commands, which comprises: first and second separately excitable control windings electromagnetically associated with the armature for moving the armature from the first to the second position when the first winding is excited and for moving the armature from the second to the first position when the second winding Is excited; a bistable multivibrator having first and second complementary inputs and first and second complementary outputs; means responsive to each occurrence of the first control signal for exciting the first input of the bistable multivibrator; means responsive to each occurrence of the second control signal for exciting the second input of the bistable multivibrator; means including first and second normally disabled switching means for individually exciting the first and second windings when the switching means are enabled; means responsive to the first output of the bistable multivibrator for enabling the first switching means; and means responsive to the second output of the bistable multivibrator for enabling the second switching means.
 2. In an electrical pattern mechanism for circular knitting machines having a rotary needle cylinder and electromagnetically actuated components acting on the needles or jacks according to control signals derived from a program carrier: a bistable multivibrator whose output states are determined by the control signals supplied by the program carrier; a monostable multivibrator having an input connected to an output of the bistable multivibrator; a resistor; a capacitor connected across the resistor; an electromagnetic winding; a transistor; winding excitation means including means for serially connecting the resistor, the winding, and the collector-emitter path of the transistor; and means for coupling the output of the monostable multivibrator to the base of the transistor. 